Anticholinergics may be used to advantage to treat a number of diseases. Particular mention may be made for example of the treatment of asthma or COPD (chronic obstructive pulmonary disease). Anticholinergics which have a scopine, tropenol or tropine basic structure are proposed for example by WO 02/03289 for the treatment of these diseases. Moreover, tiotropium bromide is particularly disclosed in the prior art as a highly potent anticholinergic. Tiotropium bromide is known for example from EP 418 716 A1.
In addition to the methods of synthesis for preparing scopine esters, disclosed in the prior art mentioned above, a process for preparing esters of scopine is disclosed particularly in WO03/057694.
The aim of the present invention is to provide an improved industrial method of synthesis which enables the compounds of general formula 1 to be synthesised more easily, in a manner which is an improvement on the prior art.